Transposition apparatus for electrical musical instrument



March 6, 1962 H. E. w. BODE 3,023,659 TRANSPOSITIQN APPARATUS FORELECTRICAL MUSICAL INSTRUMENT Filed July 11, 1960 United States Patent G3,023,659 TRANSPOSHION APPARATUS FOR ELECTRICAL MUSIAL INSTRUMENT HaraldE. W. Bode, Corinth, Miss, assignor to The gg rlitzer Company, Chicago,111., a corporation of Filed July 11, 1960, Ser. No. 41,960 5 Claims.(Cl. 84-445) This invention relates to electronic musical instrumentsand more particularly to novel apparatus especially adapted for use withkeyboard instruments such as electronic organs which enables the playerof the instrument to transpose music to different key signatures withoutnecessitating an involved mental process for each note so that eachdigital (key), actuated in normal manner, may produce a musical soundfrom a tone generator that is selectively displaced a desired andsimilar amount from the note indicated by the musical score, forexample. Musical compositions are usually written in a particular keysignature but as it is often desired to play the instrument inconjunction with other instruments or to accompany people in singing,for example, the key indicated on the score may not be suitable inparticular instances and therefore a transposition either to a higherkey signature or to a lower key signature is necessary. Whiletransposition from one octave to the next, either higher or lower, iscomparatively easy, such octave transpositions are of too large amagnitude in most if not all cases and it is necessary to operatedigitals (including adjustment for sharps and flats) that are displaceda uniform amount from the digitals indicated on the score. This is oftenan arduous task for even the professional to perform easily andaccurately and often is impossible for the amateur to play so that theexpected and desired satisfaction is obtained from the performance.

Accordingly, it is an object of this invention to provide a simple keyor pitch changing apparatus capable of easy manipulation so that even alayman may play music in any key signature by limiting himself to oneand only one key (for instance the key of C).

Another object of the invention is to provide apparatus which enables aprovision of a more versatile and improved electronic musicalinstrument.

A further object of the invention is to provide in an electronic musicalinstrument having a series of tone signal sources each of which isadapted to be associated with a frequency divider chain to provide theseveral difierent octaves of the note provided by that tone signalsource, a switching circuit which enables selection in a simple andstraightforward manner, an octave of tone signal sources correspondingto a key signature other than the one in which the music is scored andconnecting these sources to the frequency divider chains so that themusical output will be transposed as desired without the necessity ofoperating digitals other than those indicated by the score for example.

A further object of the invention is to provide in an electronic musicalinstrument utilizing a series of tone signal sources, a switchingarrangement in which the tone signal sources are selectively connectedto the digitals so that the tones produced by the digitals may be variedin an effective transposition of the music as scored.

In the preferred embodiment of the invention, an electronic organ, thereis provided a series of digitals in the form of a keyboard each of whichkeys the audio signal produced by tone signal source or frequencydivider elements to produce the desired combination of musical notes.The digitals adjacent one another produce musical sounds that are asemitone apart. In the musical inice strument of this type, the highestoctave of keys (twelve in number) is connected to a series of twelvetone signal sources or primary tone generators and each lower octave ofkeys is connected to secondary tone generators in the form of a set ofaperiodic or nonresonant frequency dividers. The frequency dividerscorresponding to each key are arranged in a chain and provide therequisite octave range of the instrument. In accordance with theinvention in addition to the series of twelve primary tone generatorsthere is provided an additional series of eleven (or twelve) tone signalsources, which will also be denominated primary tone generators in thefollowing description, whose outputs are related to the principal seriesto form a continuation of the output tone spectrum. Interposed betweenthe primary and secondary tone generators (the latter being aperiodicdividers) is a switch network inclding twelve bus bars (one for eachnote of the octave). Each bus bar also has a digital associated with itthrough which the highest octave of notes are played. Further, there isa set of swelve (or thirteen) ganged switches corresponding to at leastthe twelve possible key signatures that need to be available fortransposition purposes. A thirteenth key may be provided in order tocomplete the octave by repeating as the highest key, the key at the lowend, as is frequently found in the design of keyboards. Each switch setis arranged to selectively connect a series of twelve adjacent tonegenerators to the bus bars and each bus bar is fixedly connected to acorresponding one of the frequency divider chains. The switch sets arepreferably interlocked so that only one of them can be in operatedposition at any one time. By operating a selected set of switches aseries of twelve primary tone generators is connected to the bus barsand the secondary tone generator frequency divider chains. The series ofprimary tone generators connected to the bus bars and divider chains iseasily varied to provide effective transpositions so that a musician mayplay the keyboard instrument in the easiest manner (in the key of C forexample) and produce music transposed up a fifth, for example, to thekey of G merely through an appropriate selection of a set of switches.The apparatus provides a simple, easily operated apparatus foraccurately changing the key signature of the music so that a musicianmay adjust the musical output of the instrument to that of theassociated instruments, voices or other equipment without any involvedmental process of transposition. The apparatus of the invention thusenables the provision of an improved and more versatile electronicmusical instrument.

Other objects and advantages of the invention will be seen as thefollowing description of a preferred embodiment thereof progresses inconjunction with the drawing, in which the single figure is a schematicdiagram of the primary tone generators, switching apparatus andsecondary tone generator divider chains associated with the actuatingkey members in a preferred embodiment of the invention.

There is shown in the single figure of the drawing a series of primarytone generators 1i), twenty-three in number, which provide two octaves(minus one semitone) of musical tones in semitone intervals. Thesemitone provided by each generator is indicated by the key value on theblock If that represents the tone generator.

Also associated with the musical instrument are twelve chains 12 offrequency divider circuits (indicated by blocks 14, 16, 18) connected incascade and a series of twelve connector members or bus bars 20. Thesefrequency dividers are of the aperiodic type in that they a0 curatelygenerate output signals of one half the frequency of the input signalover a substantial range of input signal frequencies. Each frequencydivider may be a bistable multivibrator, for example, designed torespond to signals applied to its complement input and to have aresulting output of suitable harmonic content. Each bus bar 26 isconnected to a corresponding chain of frequency dividers. Thus thelowest bus bar is connected to the leftmost chain (C) of frequencydividers, the next higher bus bar is connected to the chain (C#) offrequency dividers immediately to the right of the C chain, etc. Asuitable audio control or gating means, in the form of a key element 22,for example, which is actuated by a digital on the keyboard of themusical instrument is associated with each bus bar and with eachsecondary tone generator in the frequency divider chains. Thus the audiocontrol key 24 associated with the lowest bus bar, when actuated,produces the highest note of a particular value (C); the audio controlkey 26 associated with the first frequency divider 14 in the leftmostchain, when actuated, produces the same note value but one octave lower;the key 28 associated with the next divider 16 when actuated alsoproduces the same note in the next lowest octave and so forth. It willbe understood that additional secondary tone generators may be added tothe frequency divider chains so that the number of octaves of theinstrument may be eX- tended as desired. As illustrated these keys 24,26, 28 are positioned in the C location on the conventional keyboardarrangement. The second bus bar and the second chain of frequencydividers are actuated by keys in the C# keyboard location; the third busbar and the third chain of frequency dividers are actuated by keys inthe D location; etc.

The primary tone generators are adapted to be connected to the audiocontrol mechanism through a switching arrangement which comprises aplurality of ganged switches 30, one switch corresponding to each keysignature as indicated on the figure. Each switch element of the gangedswitches 36" has a contact 32 permanently secured to the correspondinglocation on the proper bus bar so that when a ganged switch is operatedthe series of bus bars 20 are connected to a redetermined series of tonegenerators through contacts 32. Each primary tone generator is connectedto one or more switches 30 so that each primary tone generator notevalue is connected to a total of twelve switches. Thus the primary tonegenerator for note E is connected to one switch contact of all twelveswitches while the tone generator for the lower P note is connected toonly one switch element while the higher F note generator is connectedto a contact of each of the other eleven switches. In like manner thelower Fit generator is connected to the elements of two switches and thehigher F# generator is connected to elements of the remaining tenswitches. The switches 3t! may be perated by push buttons 34, or forinstance by the keys of a little single octave keyboard with appropriatecoloring of naturals and sharps, or by solenoids, foot controls or othersuitable means. These switch operating means are preferably interlockedso that only one ganged switch is operated at any one time. Associatedwith each switch operator means is a suitable marking or otherindication of the resulting degree of effective transposition as thearrangement enables the sound of the music to be shifted upwardly ordownwardly as desired in accordance with which set of ganged switches isselected.

For example, if the leftmost ganged switch, denominated 'F, isdepressed, as shown in the drawing, the left most primary tone generatorF is connected to the C bus bar and the C chain of frequency dividers.Thus depressing any C digital on the keyboard to close the keying means24, 26, 28 will sound the note F, its octave depending on whichparticular digital is depressed. Similarly the C# digitals will soundFit notes, etc. The following table sets forth the various notetranspositions which are achieved by operating various pitch selectionswitches, the body of the table indicating the note that is sounded bydepressing the digital in the leftmost column when the horizontal Aportion of the wiring and several switches in the central part of theswitching arrangement have been omitted in order that a representativeportion of the switching arrangement may be clearly illustrated. As thecircuitries not shown in detail are connected in the same pattern asthat shown it is believed that those of ordinary skill in the art willhave no trouble in practicing the invention by following this teaching.

In summary there are twenty-three (or twenty-four) primary tonegenerators, twelve adjacent ones of which are connected through theswitching arrangement to bus bars 29 and divider chains 12 when a singleganged switch 30 is operated. This simple arrangement enables theselcctive shifting of the tones produced as the keyboard digitals of theintsrument are operated through an entire octave in a transposingoperation.

Thus it will be seen that the invention provides a very simple andstraightforward apparatus which may be used for the selection of variouskey signatures so that a transposition effect may be easily obtainedeven by persons comparatively unskilled in the art of playing theelectronic musical instrument. It will be understood by those havingordinary skill in this art that various modifications of the disclosedembodiment of the invention may be made therein. Therefore, while therehas been shown and described herein a preferred embodiment of theinvention it is not intended for the invention to be limited thereto orto details thereof and departures may be made therefrom within thespirit and scope of the invention as defined in the claims.

I claim:

1. In an electronic musical instrument, apparatus for enabling aneffective transposition of output musical notes relative to music asscored without the actuation of digitals other than those indicated onthe score comprising in combination, a plurality of sets of secondarytone generators, each set including a corresponding plurality ofsecondary tone generators connected in cascade arrangement, a bus barconductor means connected to each said set of secondary tone generators,a series of primary tone generators greater in number than the number ofsets of secondary tone generators, each said primary tone generatorbeing adapted to generate an electrical signal adapted to produce apredetermined musical note and said primary" tone generators beingarranged relative to one another to produce a continuous series ofmusical notes, ganged switch transposition means adapted tosimultaneously connect said bus bar conductor means to a correspondingnumber of serially related primary tone generators to apply theelectrical signals from said primary tone generators to said bus barsand the associated secondary tone generators, a multiplicity of digitalsarranged in keyboard relationship in repetitive groups, the number ofdigitals in each group being equal to the number of bus bar connectormeans, audio keying means operable by a digital associated with eachsaid secondary tone generator, and audio keying means operable by adigital in the highest group of said keyboard associated with each saidbus bar conductor means for enabling the generation of audible musicalnotes related to the signals provided by the connected primary tonegenerators in response to the actuation of said digitals.

2. In an electronic musical instrument, apparatus for enabling aneffective transposition of output musical notes relative to music asscored without the actuation of digitals other than those indicated onthe score comprising in combination, twelve sets of aperiodic frequencydivider circuits, the frequency divider circuits in each set beingconnected in cascade arrangement, twelve bus bar conductor means, oneconductor means being connected to each said set of frequency dividers,a series of primary tone generators greater in number than the number ofsets of frequency dividers, each said primary tone generator beingadapted to generate an electrical signal adapted to produce apredetermined musical note and said primary tone generators beingarranged relative to one another to produce a continuous series ofmusical notes, ganged switch transposition means adapted tosimultaneously connect said bus bar conductor means to a correspondingnumber of serially related primary tone generators to apply theelectrical signals from said primary tone generators to said bus barsand the associated frequency dividers, a multiplicity of digitalsarranged in keyboard relationship in repetitive groups of twelve each,audio keying means operable by a digital associated with each saidfrequency divider, and audio keying means operable by a dgital in thehighest group of said keyboard associated with each said bus barconductor means for enabling the generation of audible musical notesrelated to the signals provided by the connected primary tone generatorsin response to the actuation of said digitals.

3. In an electronic musical instrument, the combination comprising aseries of twenty-three primary tone generators, each said primary tonegenerator being adapted to produce a predetermined musical note onesemitone different from that produced by the immediately adjacentprimary tone generator so that said primary tone generators are arrangedto produce a continuous series of musical notes in semitone intervals, aset of digitals arranged in keyboard form in octaves with twelvedigitals to the octave, twelve sets of secondary tone generators, eachset including a corresponding plurality of secondary tone generatorsarranged to produce that same musical note in descending octaverelationship, twelve conductor means, each said conductor means beingconnected to a particular set of secondary tone generators so that thesecondary tone generators of that set are arranged to produce the samenote value in lower octaves as is produced by the conductor means towhich that set is connected, audio keying means operable by a digital inthe highest octave of the keyboard associated with each said conductormeans, audio keying means associated with each said secondary tonegenerator operable by each digital in the lower octaves corresponding tothe conductor means to which said secondary tone generator is connected,and switch means adapted to connect said conductor means to twelveserially related primary tone generators for enabling the effectiveselection of an appropriately related signal from a primary tonegenerator to provide an output musical note in response to the actuationof a particular digital.

4. in an electronic musical instrument, the combination comprising aseries of twenty-three primary tone generators, each said primary tonegenerator being adapted to produce a predetermined musical note onesemitone different from the immediately adjacent tone generator so thatsaid tone generators are arranged to produce a continuous series ofmusical notes in semitone intervals, a set of digitals arranged inkeyboard form in octaves with twelve digitals to the octave, twelvesecondary tone generator chains, each said chain change including aplurality of aperiodic frequency dividers connected in cascadearrangement, audio keying means associated With each said frequencydivider, each said keying means adapted to be operated by a digital,twelve conductor means, each having associated therewith an audio keyingmeans adapted to be operated by a digital in the highest octave of thekeyboard, each said conductor means being connected to a particularfrequency divider chain so that the frequency dividers of that chain arearranged to pro duce the same note value in lower octaves as is producedby the connected conductor means, and switch means adapted to connectsaid conductor means to twelve serially related primary tone generatorsfor enabling the effective selection of a primary tone generator orconnected frequency divider to provide an output musical note inresponse to the actuation of a particular digital.

5. In an electronic musical instrument having a series of digitalsarranged in octaves as audio output keying devices for producingindividual and distinct musical notes, a pitch selection apparatusincluding an aperiodic frequency dividing means connected to eachdigital in all the octaves of the instrument except the highest, thefrequency dividing means which are adapted to produce the same notesbeing connected in a cascaded chain arrangement, means for connectingeach said frequency divider chain arrangement to the digital in thehighest octave that is adapted to produce the same note as said chain, aseries of electronic tone generators adapted to provide signals to saiddigitals for the production of said musical notes, and switch meansadapted to selectively connect a serial group of tone generators equalin number to the number of notes in an octave to said connecting meansto pro vide audio signals from said generators via said connecting meansand said frequency dividers in response to the actuation of saiddigitals for enabling an effective transposition relative to saiddigitals of the key in which music is to be played.

No references cited.

